Naomi Watts feels pressured by Princess Diana role

The 43-year-old actress was hesitant to accept the role of the late Princess of Wales - who died in a car crash in Paris in 1997 - in upcoming biopic 'Caught In Flight' because she was so worried about the public's reaction and whether it might upset Diana's sons, Prince William and Prince Harry.

She confessed: ''It's high pressured. I tried to say no, then changed my mind. She led a fascinating life, and she's a fascinating character. It was quite an undertaking. I also had to have my eyebrows shaved in the middle.

''It took me some time to decide whether to do it. This is the most famous woman of our times.''

However, the Golden Globe nominated star says her new disaster drama 'The Impossible', based on a family's real life struggle to reunite in the aftermath of the Indian Ocean Tsunami in December 2004, was even tougher to shoot because of her phobia of drowning.

Naomi revealed to the Daily Mail newspaper: ''It was intense - lots of underwater filming and climbing trees. I'm a tomboy at heart. I have an older brother and was never interested in girl things, so climbing trees didn't bother me. But being underwater...''